Wire used in electric weld systems is frequently stored on spools for continuous delivery for weld creation, wherein current is delivered via the wire to the workpiece to complete the weld circuit. As the wire is electrically live, contact with any conductive surfaces outside of the electric weld circuit (e.g., steel plates and structures) can cause shorting of said weld circuit, resulting in consequent damage to one or more components within the weld system and/or deleterious weld creation. The wire must be isolated electrically to prevent these short circuit events outside of the weld circuit from occurring, and this isolation must remain effective over the entire dispensing cycle of the wire on the spool. Many spool, spool mounting, and wire path control designs have been employed to achieve these goals.
Of particular interest is the inside end of the welding wire wound on a spool. This end must be isolated from short circuit events, and must be retained adequately in an isolated state over the entire dispensing cycle of the wire on the spool. As such, it must not be permitted to become detachedly released during the dispense cycle of the wire on the spool.
In one exemplary spool design, a hole is disposed completely through the barrel that allows seating a hook at the wire end through a slot into the spool core. In this conventional application, electrical isolation of the wire is achieved by constraining the hook end of the wire to a very narrow position within a keyway in the hub onto which the spool is installed. It is difficult to constrain movement of the hook end within this small window and thereby achieve electrical isolation. In addition, since the wire end has to be kept short to prevent short circuiting, the end can become detachedly released when the wire nears the end of spool, which is undesirable prior to completely consuming the wire. In one exemplary means to compensate for this shortcoming, more wire than that which is required for a weld cycle can be wound on the spool to insure there is sufficient wire remaining as a weld nears completion. This solution, however, results in unnecessary costs as the extra wire is generally scrapped at the conclusion of the weld.